Richard Griffiths, the portly British actor who won acclaim for his stage performances in "The History Boys," "Equus" and many other productions, was one of the most beloved figures in the London theater. His numerous performances ranged from contemporary dramas to classical roles, to which he brought a sense of cutting intelligence and understated humor.

Griffiths died in England on Thursday at 65. The actor died of complications following heart surgery, according to reports.

His stage colleagues remembered him as a dedicated actor who was also a witty and voluble raconteur among his friends.

Danny DeVito, who starred alongside Griffiths in last year's London revival of Neil Simon's "The Sunshine Boys," said in a phone interview that "it was a gift for me to know him. I'm so sad. It was the most positive kind of fun. We clicked from the very moment we met when we did 'Sunshine.' We had such fun on stage."

The actor described Griffiths as "a hysterical man -- ironic and intelligent. He had an effervescent energy." DeVito said that after performances of "Sunshine" at the Savoy Theatre, "we would sit and talk, with ice and gin and lime. We would sit and talk for hours."

Both actors were set to reprise their roles in "The Sunshine Boys" at the Ahamanson Theatre in Los Angeles starting in September.

Douglas Baker, producing director at Center Theatre Group, said in an interview that the company's "thoughts right now are with Richard's family ... . We will be meeting with the producers of the show, and the creative team, soon -- certainly with the next weeks -- to discuss the future planning of the production."

DeVito said he recently visited Griffiths and his wife at their home outside London. "I flew over because I heard he wasn't feeling well ... we were excited that we were going to be doing ['Sunshine'] again. We talked about a lot of different things -- we talked about American history. He knew more about it than I did."

Fiona Shaw, who costarred alongside Griffiths in the "Harry Potter" movies as Harry's "muggle" aunt and uncle Petunia and Vernon Dursley, said she and Griffiths were good friends whose paths often crossed in the London theater scene.

"He was a philosopher clown," Shaw said by phone from New York. "He was incredibly knowledgeable about history, science, almost everything. He had a huge ambition and was a total delight in what he did. And that's what was clearly communicated to audiences. He dedicated himself to the theater."

Shaw said that Griffiths was "incredibly funny -- sometimes he would hold up shooting on 'Harry Potter' so that he could finish a joke. His mind was a weaving of many different stories."

Griffiths worked a number of times with Nicholas Hytner, director of London's National Theatre. Hytner directed Griffiths in Alan Bennett's "The History Boys," for which the actor won a Tony Award when the play transferred to Broadway in 2006.

"His currency as an actor was truth; as a colleague it was hilarity," Hytner said in a statement.

"His anecdotes were legendary. They were, literally, endless. They would go on for hours, apparently without destination, constantly side-splitting ... . I'm desperately sad that I'll never hear another of his stories or see another of his peerless performances."